Fastener system

ABSTRACT

A fastener system shifting shear stresses away from a collet body and provides clamping action to targeted structures. The fastener system includes feet in the collet body that mate with openings in a sleeve at least partially surrounding the collet body. The sleeve or the collet body includes interior threads that engage with a stud that is configured to extend through the collet body and bend the feet such that they project outward from the sleeve openings in an engaged configuration.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority to U.S. Provisional ApplicationNo. 62/558,762, entitled “Fastener System”, and filed on Sep. 14, 2017.The entire contents of the above-listed application are herebyincorporated by reference for all purposes.

FIELD

The present description relates generally to a fastener system designedto clamp two structures.

BACKGROUND AND SUMMARY

Many manufacturing fields use fasteners, such as blind fasteners, forsecuring two objects to one another. Blind fasteners are particularlyuseful when only one side of a joint is accessible. One application ofsuch fasteners is in the aerospace industry where removable colletfasteners are utilized to secure floor panels to underlying floor beams.Using removable fasteners to secure floor panels to the floor beamsincreases the modularity of the aircraft's cabin. Resultantly, theaircraft's interior may be altered at a late stage in manufacturing toincrease the adaptability of aircraft manufacturing processes.Therefore, the manufacturer or in some cases the customer may alter thefloor panel layout to reconfigure the airplane when desired. In otherexamples, the collet fasteners may be used to attach wing components,fuselage components, pylons, etc., providing the same benefits ofincreased manufacturing adaptability. Previous blind fasteners haveincluded a stud threading into a collet body having fingers thatradially expand when said threading occurs. When expanded the fingersslide under a lower structure to act as a lower clamping arm while asurface of the stud head acts as an upper clamping arm to retain anupper structure.

However, the inventors have recognized several drawbacks with previousblind fasteners. For instance, the collet body may be susceptible toshear stresses due to external structural loading and the externalposition of the collet body in the fastener. The collet body containsmultiple flexible arms that, as a necessity of the prior fasteners,operate independently from one another. As such, they are disjointed anddo not communally share shear strength with one another. When in shear,only the flexible arms directly in contact with the load path can resistthe shearing force. In the previous fasteners, the flexible arms aretangentially positioned at a maximum distance from a line created by theintersection of the shear force vector acting through the center of thecollet body. These flexible arms resist very little, if any, of theshearing force. As a result, individual flexible legs in prior fastenerscan become substantially damaged and fail, or suffer other forms ofdamage (e.g., permanent deformation) that impede desired functions ofthe flexible legs. The stud may be difficult to remove and in some casesbecome stuck within the collet body when the fastener clamps twoadjoining structures. Furthermore, the fingers in the collet body may bedifficult to insert into a bore due to the exposed edges of the colletbody fingers now deformed and protruding radially outward, due to damagesustained in resisting shear.

Facing the aforementioned challenges the inventors developed a fastenersystem. The fastener system includes a sleeve with a sleeve opening anda collet body at least partially enclosed within the sleeve, the colletbody including a crown having a crown opening, and a cantilever legextending from the crown and including a foot configured to mate withthe sleeve opening when the fastener system is in an engagedconfiguration. The fastener system also includes a stud extendingthrough the crown opening and includes a threaded section engaging withan interior threaded section in at least one of the collet body and/orthe sleeve. In this way, the cantilever leg may be protected by thecollet body and shear stresses on the cantilever leg may be decoupledfrom the collet body while the system exerts a clamping force on twostructures. In particular, the sleeve protects the collet body fromshear stresses across the flexing part of the cantilever leg createdfrom sideways forces in the structures that are being fastened. Thus,the longevity of the fastener described herein, when compared toprevious fasteners that suffer from shear stresses degrading the abilityof the cantilever leg to flex or retain its memory shape, can beincreased. Moreover, the fastener also allows the stud to be easilythreaded and unthreaded without binding, enabling the system to beeasily and efficiently installed as well as removed. Moreover, when thecollet body is constructed out of a nonmetallic material, such as apolymer, the sleeve protects the collet body from abrasive wear duringinsertion and removal, decreasing the likelihood of fastenerdegradation.

In one example, advancing engagement between the threaded section of thestud and the interior threaded section decreases a distance between anupper clamping surface and a lower clamping surface, the lower clampingsurface is included in the foot and the upper clamping surface isincluded in the stud. In this way, the clamping force generated by thefastener system can be varied to provide a desired amount of couplingbetween two components while the shear stresses are, to a large extent,uncoupled from the collet body.

In another example, the stud may include a reduced diameter section(e.g., unthreaded section) positioned near a bushing engagement zone.The reduced diameter section is configured to allow the stud to freelyspin when the stud is unthreaded and disengaged from the interiorthreaded section. Allowing the free rotation of the stud in this mannerprevents the stud from damaging the sleeve or collet body duringdisengagement.

In another example, the fastener system may include an auxiliarystructure at least partially extending around the sleeve and including alower surface acting as a lower clamping surface. The auxiliarystructure enables quick and efficient removal of the system after it isunclamped and also may require less machining of the bores in theclamped structures. In this way, the fastener system may be utilized ina broader range of structures.

It should be understood that the summary above is provided to introducein simplified form a selection of concepts that are further described inthe detailed description. It is not meant to identify key or essentialfeatures of the claimed subject matter, the scope of which is defineduniquely by the claims that follow the detailed description.Furthermore, the claimed subject matter is not limited toimplementations that solve any disadvantages noted above or in any partof this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an exploded view of a first example fastener system.

FIG. 2 shows a view of a collet body assembled with a sleeve included inthe fastener system, depicted in FIG. 1.

FIG. 3 shows the first example fastener system, depicted in FIG. 1, inan assembled state.

FIG. 4 shows a cross-sectional view of the fastener system, illustratedin FIG. 3.

FIG. 5 shows an exploded view of the first example fastener system,illustrated in FIG. 1, with a retainer.

FIG. 6 shows the fastener system, illustrated in FIG. 5, in an assembledstate.

FIG. 7 shows a cross-sectional view of the fastener system, depicted inFIG. 6.

FIGS. 8-14 show a sequence of tooling steps where the third fastenersystem is used to clamp two structures together.

FIG. 15 shows an exploded view of a second example fastener system.

FIG. 16 shows the second example fastener system, depicted in FIG. 15,in an assembled state.

FIG. 17 shows a cross-sectional view of the second example fastenersystem, depicted in FIG. 16.

FIG. 18 shows a third example fastener system including an auxiliarystructure.

FIGS. 19 and 20 show a cross-section view of the fastening system,depicted in FIG. 18, in two states of disengagement.

FIGS. 21 and 22 show a sequence of tooling steps where the thirdfastener system is used to clamp two structures together.

FIG. 23 shows a fourth example fastener system.

FIGS. 24 and 25 show a fifth example fastener system including anauxiliary structure.

FIG. 26 shows another example of a sleeve and collet body included in afastener system.

FIG. 27 shows a sixth example fastener system including a stud with anupper and lower threaded section.

FIGS. 28-33 show a seventh example fastener system including a retainingring.

FIGS. 34-37 show a clamping sequence in an eighth example fastenersystem.

FIGS. 38-43 show a ninth example fastener system including sleeve with athreaded section.

FIGS. 44-47 show a tenth example fastener system with a split colletbody.

FIG. 48 shows a method for installing and removing a fastener system.

FIGS. 1-47 are drawn approximately to scale, however other relativedimensions may be used in other embodiments.

DETAILED DESCRIPTION

The following description relates a fastener system designed to decoupleshear stresses from a collet body and provide clamping engagement totargeted structures. Decoupling of the shear stresses from the colletbody enables quick, efficient, and unobstructed engagement anddisengagement of clamping arms in the system. In particular, thefastener system is designed to decouple shear forces from a weakersection (i.e., cantilever legs) and place the same shear forces onto amuch stronger section (i.e., a sleeve). As a result, the fastener systemhas excess capacity, enabling the system to carry additional shearforces. The fastener system includes a collet body that fits within asleeve. The collet body is provided with feet on the end of cantileverlegs extending downward from a crown. When the fastener system is in anengaged configuration and a stud is threaded into the collet body andsleeve, the feet protrude through openings in the sleeve. The sleeveprotects the collet body and prevents shearing forces from acting on thecollet body while allowing the feet to function as lower clamping arms.An underside of the head of the stud or an auxiliary structuresurrounding the sleeve may act as an upper clamping arm. As the stud isfurther threaded into the collet body and sleeve, a distance between thefeet and a head of the stud decreases. In this way, the clamping forcegenerated by the fastener system can be varied to provide a desiredamount of engagement between two structures. The stud may also includean unthreaded section at one end. The unthreaded section is designed toenable free rotation of the stud with regard to the sleeve and colletbody when the stud is disengaged (e.g., fully backed out) from aninterior threaded section in the sleeve or collet body. Consequently,the stud may be prevented from damaging the sleeve or collet body duringdisengagement (e.g., maximum disengagement).

FIGS. 1-4 show a first example of a fastener system. FIGS. 5-7 show thefirst example of the fastener system with a retainer functioning tosecurely retain a collet body in a sleeve. FIGS. 8-14 show an engagementsequence where the fastener system engages with structures. FIGS. 15-17show a second example of a fastener system where the collet bodyincludes a threaded section designed to engage with threads in the stud.FIGS. 18-22 show a third example of the fastener system including anauxiliary structure. FIG. 23 shows a fourth example of the fastenersystem again including an auxiliary structure. FIGS. 24-25 show a fifthexample of the fastener system where the auxiliary structure includes anupper threaded section. FIG. 26 shows a sixth example of the fastenersystem including a collet body with a pair of cantilever legs designedto mate with a pair of openings in a sleeve. FIG. 27 shows a seventhexample of the fastener system including a stud with a free-spin zoneand an auxiliary structure. FIGS. 28-33 show an eighth example of thefastener system including a retaining ring and a stud including anincreased diameter threaded portion. FIGS. 34-37 show an engagementsequence in a fastener system. FIGS. 38-43 show a ninth example of afastener system. FIGS. 44-47 show a tenth example of the fastener systemincluding a split collet body. FIG. 48 shows a method for operation of afastener system to assemble the fastener and then clamp and unclamp thefastener from structures.

Turning to FIG. 1, an exploded view of a fastener system 100 isillustrated. The fastener system 100 includes a stud 102, a sleeve 104,a collet body 106, and a bushing 108. Each of the components in thefastener system 100 share a common central axis 109.

The stud 102 includes a first end 111 and a second end 112. A head 110is included in the first end 111. The head includes a tool interface114. In the illustrated example, the tool interface 114 is a splinedrecess. However, other suitable types of interfaces have beencontemplated such as hexagonal recesses, slotted recesses (e.g., aPhillips type recess), a square recesses, external spine or hex for usewith conventional sockets, etc. The tool interface 114 is designed toreceive a driver (e.g., splined driver, hexagonal driver, etc.,)inducing rotation (e.g., clockwise or counterclockwise rotation) of thestud 102 about the central axis 109.

The head includes an upper surface 116. In the illustrated example, theupper surface 116 is planar. However, other contours of the uppersurface of the head have been contemplated. The stud 102 furtherincludes a threaded section 118, a first reduced diameter section 120,and a second reduced diameter section 122 (e.g., bushing engagementzone). In the depicted example, the first reduced diameter section isunthreaded. However, in other examples, at least a portion of the firstreduced diameter portion may be threaded.

The second reduced diameter section 122 is configured to mate with thebushing 108 at the second end 112 of the stud 102. As illustrated, thesecond reduced diameter section 122 has a cylindrical shape with anouter diameter 124 that is less than an outer diameter 126 of the firstreduced diameter section 120. However, other contours of the secondreduced diameter section 122 have been contemplated. Additionally, anouter diameter 128 of the threaded section 118 is greater than the outerdiameter 126 of the first reduced diameter section 120, in theillustrated example. In this way, the second end 112 of the stud 102 maytravel through a central aperture 130 in the sleeve 104 and a crownopening 132 in a crown 134 of the collet body 106.

The sleeve 104 includes a first end 136 and a second end 138. The firstend 136 includes a facetted collar 140. The facetted collar 140 includesplanar surfaces 142. In the depicted example, the planar surfaces 142form a hexagonal shape. However, numerous shapes have been contemplated.Such as square shapes, pentagonal shapes, octagonal shapes, etc.Furthermore, the collar may include lobes or other protrusions that arenot planar, in other examples. The surfaces on the collar, being planaror non-planar, are configured to limit (e.g., substantially inhibit)rotation of the sleeve 104 while allowing axial translation duringinstallation and removal of the fastener system. The facetted collar 140may be mated with a bore in a structure, having a corresponding geometry(e.g., hexagonal shape) to limit (e.g., substantially inhibit)rotational movement about axis 109 of the sleeve 104 and thereforecollet body 106 while the stud 102 is rotated or vice-versa andcorrespondingly facilitates axial translation of the sleeve. However, inother examples, the facetted collar 140 may be gripped by a tool, heldby a tool body, or held by an auxiliary structure to inhibit movement ofthe sleeve 104 while the stud 102 is rotated while allowing axialtranslation of the sleeve.

The sleeve 104 further includes an interior threaded section 144. Theinterior threaded section 144 in the sleeve 104 is designed to engagewith the threaded section 118 in the stud 102 when the stud is insertedinto the central aperture 130 and rotated to initiate engagement.

The sleeve 104 also includes opening 146 (e.g., sleeve openings)configured to mate with feet 148 in the collet body 106, discussed ingreater detail herein. Additionally, the openings 146 include an upperside 150, lower side 152, and lateral sides 154. The sides of theopenings limit (e.g., substantially inhibit) rotational movement aboutaxis 109 of the feet 148, when the collet body 106 is mated with thesleeve 104. Furthermore, the openings 146 radially extend outwardthrough a housing 156 of the sleeve 104. Additionally, the openings 146are equally spaced around the housing 156, in the illustrated example.However, unequal spacing of the openings has been contemplated.Additionally, the fastener system 100 includes a corresponding number ofopenings 146 in the sleeve 104 and feet 148 in the collet body 106.However, the fastener system 100 may include a mismatched number of feetand openings, in other examples. Furthermore, the fastener system 100includes three openings and three feet, in the illustrated embodiment.However, alternate numbers of feet and/or openings have been envisioned.

The collet body 106 includes cantilever legs 158 extending in an axiallydownward direction 160 from the crown 134. As referred to herein anaxially downward direction is an axial direction extending toward thebushing 108 or other lower end system components while an axially upwarddirection 162 is an axial direction extending toward the head 110 of thestud 102 or other upper end system components. An exemplary radial axis163 is also provided for reference. It will be appreciated that thecentral axis 109 may be parallel to a gravitational axis, in someexamples. However, in other examples, alternative orientations of thecentral axis have been contemplated. The cantilever legs 158 areconfigured to act as springs and generate return forces in response toradial bending in both inward and outward directions. However, in FIG.1, the cantilever legs 158 are in a neutral position. In one example,the cantilever legs 158 may be pre-bent and/or heat-treated to enablethe legs to achieve the neutral position, shown in FIG. 1. Theheat-treating may also increase the spring action in the legs. It willalso be appreciated that the cantilever legs 158 will return to theirneutral states after being deformed (e.g., bent inward and outward). Inother examples, the cantilever legs 158 may be in a neutral state whenthe fastener system is in the engaged configuration, such as when thefastener system is constructed out of a polymer.

As depicted, the cantilever legs 158 are spaced away from each othersuch that gaps 164 are formed there between. The cantilever legs 158include feet 148 protruding radially outward from lower end and outersections of the cantilever legs 158. The feet 148 are contoured to matewith the openings 146 in the sleeve 104. Specifically, the feet 148 eachinclude an upper surface 166, side surfaces 168, a peripheral surface170, and a lower surface 172, in the illustrated example.

The cantilever legs 158 additionally include a hinge zone 174. The hingezone 174 may be formed naturally or enhanced adjacent to where thecantilever legs 158 join to crown 134 of collet body 106. This hingezone 174 enables the cantilever legs to flexibly swing in an arc duringradial loading and unloading. In one example, the hinge zone 174 mayinclude a tapered section (e.g., radially tapered section) thatfacilitates leg flexion.

The collet body crown 134 includes the crown opening 132 having an innerdiameter 176 that is greater than an outer diameter 128 of the threadedsection 118 of the stud 102. In this way, the crown opening 132 is sizedto receive the stud 102. Additionally, the crown has an annular shape,in the illustrated example. However, alternative crown contours havebeen contemplated. Furthermore, the crown opening is sized to receivethe bushing 108, in the depicted example. That is to say, that an outerdiameter 178 of the bushing 108 is smaller than the inner diameter ofthe crown opening 132. However in other instances, the crown 134 may besized to retain the bushing 108 such that the inner diameter 176 of thecrown opening 132 is less than the outer diameter 178 of the bushing108. As such, the crown may be configured to limit axial movement of thestud 102. Additionally, the central aperture 130 in the sleeve 104 has asmaller diameter 177 than the outer diameter 178 of the bushing 108. Inthis way, the axial movement of the bushing upwards through the collarof the sleeve may be inhibited.

The bushing 108 has an annular shape and includes an opening 180 sizedto mate with the second reduced diameter section 122 of the stud 102, aspreviously discussed. More specifically, the bushing 108 may be pressfit, braised, pinned, bonded, threaded, and/or welded to the stud 102.Thus, the bushing 108 may be permanently or removably attached to thestud 102. The bushing acts to lock the components of the system togetherto form a cohesive unit, especially while the system is in a disengagedconfiguration. The bushing 108 may also include a peripheral surface 182that is contoured to interact with the cantilever legs 158 and push themin an outward direction when slid through the collet body. In oneexample, the peripheral surface 182 may be tapered in a downwarddirection. In other examples, the bushing 108 may not interact with thecantilever legs 158 during engagement.

Additionally, the components of the fastener system may be constructedout of a similar material such as metal (e.g., steel, aluminum, etc.,),a polymer, etc., in one example. However, in other examples, the stud102, sleeve 104, collet body 106, and/or bushing 108 may be constructedout of different materials. For instance, the sleeve may be constructedout of aluminum while the collet body 106 may be constructed out of amore spring-biased material, such as steel. Moreover, the materials usedto construct the different components in the fastener system may bechosen based on end use requirements. It will be appreciated that forstructural applications (e.g., large load bearing structures) thefastener system may be constructed out of steel. On the other hand, whendesigned for commercial applications the fastener system may employplastics. Further, in other examples, the fastener system may have ahybrid material construction where both plastic and metal are utilized.Furthermore, when plastic collet bodies, a possibility in the commercialsector, the legs may be in an open position in an engaged and disengagedconfiguration and flex closed when the collet body is inserted into thesleeve, or when the system is inserted/removed from a bore. In thisinstance, the plastic may be designed to be easily flexed (e.g., pushedor pulled) by a person to cause the cantilever legs to flex inward andthus allow easy egress of the fastener through the bore.

FIG. 1 also shows an automated tooling apparatus 184 that may be used tomanipulate the fastener system and carry out the methods describedherein. The tooling apparatus 184 may include a processor 186 and memory188 (e.g., non-transitory memory) storing instructions executable by theprocessor. It will be appreciated that the automated tooling apparatus184 may further include tooling attachments, arms, carriages, etc., formanipulating the fastener system.

FIG. 2 shows a view of the collet body 106 partially mated with thesleeve 104. The partial mating of the collet body 106 with the sleeve104 is induced by bending the cantilever legs 158 inwardly toward thecentral axis 109 and sliding the collet body 106 into the sleeve in anupward direction. In the illustrated example, the feet 148 are bentinwardly toward the central axis 109 such that side surfaces 168 ofsuccessive extensions are adjacent to one another but still maintain aslight gap there between. However, in other examples, the cantileverlegs 158 may be bent such that the side surfaces 168 may be in contactor near contact during the mating procedure. Additionally, peripheralsurfaces 170 of the cantilever legs 158 are in contact with an innersurface 201 of the sleeve 104. Furthermore, the inner surface 201 of thesleeve 104 may have a greater diameter than the interior threadedsection 144 of the sleeve 104, shown in FIG. 1. Moreover, the innersurface 201 of the sleeve 104 may also have a diameter 210 that islarger than the outer diameter 190 of the crown 134 of collet body 106,shown in FIG. 1. FIG. 2 shows an expanded view 202 of a portion of thesleeve 104 and the collet body 106 to assist in viewing of specificfeatures of the system. In some of the figures described belowadditional expanded views are show to achieve the same purpose.Redundant descriptions of these views are omitted.

FIG. 3 shows the fastener system 100 of FIG. 1 assembled in a disengagedconfiguration. In the disengaged configuration the feet 148 onlypartially extend through the openings 146 of the sleeve 104. FIG. 3 alsoshows the stud 102 partially threaded into the sleeve 104.

FIG. 3 shows the head 110 of the stud 102 having a lower surface 300. Itwill be appreciated that the lower surface 300 may act as a clampingsurface in the fastener system 100. The lower surface 300 includes aportion that tapers in a downward direction and a portion that extendsinwardly. However, other lower surface contours have been contemplated,such as a flat surface.

Aside from the openings 146, the sleeve 104 includes a continuousexternal surface 302 that circumferentially surrounds the portions ofthe collet body besides the feet 148. Using a sleeve 104 contoured inthis manner enables the collet body to be protected from externalforces, such as shear forces. As such, the sleeve 104 acts to decouplethe cantilever legs of the collet body from shear stresses when used forclamping two structures. In particular, the shear forces are for themost part decoupled from a weaker section (e.g., cantilever legs) andplaced onto a stronger section (e.g., the sleeve). As a result, thefastener system has excess capacity, enabling the system to carryadditional shear forces. As described herein sheer stress is thecomponent of stress coplanar with a material cross-section.Consequently, the stud 102 may be more easily unthreaded from the sleeve104. However, in other examples the sleeve 104 may include additionalvoids that may reduce the weight of the sleeve. FIG. 3 also shows theviewing plane 304 indicating the cross-sectional view illustrated inFIG. 4.

FIG. 4 shows a cross-sectional view of the fastener system 100, shown inFIG. 3. The threaded section 118 of the stud 102 is shown engaged withthe interior threaded section 144 of the sleeve 104. The second end 112of the stud 102 having the bushing 108 attached thereto, is also shownpositioned within the crown 134 of the collet body 106.

Additionally, FIG. 4 illustrates the fastener system 100 in thedisengaged configuration where the cantilever legs 158 are not radiallyloaded by the stud 102. In the disengaged configuration outer surfaces400 of the cantilever legs 158 are at least partially spaced away froman inner surface 201 of the sleeve 104. Furthermore, in the disengagedconfiguration the feet 148 only partially extend through the openings146 such that they do not radially extend beyond an outer surface 404 ofthe sleeve 104. In this way, the fastener system 100 may be easilyinserted through bores in structures slated for clamping by the system.However, in other examples, in the disengaged configuration the feet 148may slightly protrude from the openings such that movement of the systemthrough bores would urge the feet back into the openings.

Furthermore, when the feet 148 partially extend through the openings146, the openings function to limit the movement of feet 148 andtherefore collet body 106. Thus, the relative positions of the sleeve104 and the collet body 106 can be essentially fixed to one another whenthe feet 148 are partially mated as well as fully mated with theopenings 146.

The first reduced diameter section 120 (e.g., unthreaded section) of thestud 102 is also designed to allow the stud to freely rotate. This maybe particularly useful when unthreading the stud during removal whenpeople or automated tooling machines fail to vary the applied torquewhile backing out the stud 102. As such, the free spin feature preventsthe tool from over torqueing the stud during removal and damaging thesystem. To enable the free rotation of an axial length 406 of the firstreduced diameter section 120 on the stud is equal to or greater than anaxial length 408 of the interior threaded section 144 of the sleeve 104.The free spin feature may be included in any of the examples orcombinations of the examples of the fastener system, described herein.However, in other instances, as described in greater detail herein, thefastener system may be designed with a hard stop feature that does notallow the free rotation of the stud.

FIGS. 5-7 show an example of the fastener system 100 with a retainer500. Specifically, FIG. 5 shows an exploded view of the fastener system100, FIG. 6 shows an assembled view of the fastener system depicted inFIG. 5, and FIG. 7 shows a cross-sectional view of the fastener system,illustrated in FIG. 6. Viewing plane 600 shown in FIG. 6 indicates thecross-section of FIG. 7. The fastener system 100 is again shown toinclude the stud 102, sleeve 104, collet body 106, and bushing 108. Theretainer 500 includes prongs 502 configured to extend through gaps 164between the cantilever legs 158 in the collet body 106. Consequently,the collet body 106 may be even more securely retained within the sleeve104.

FIGS. 8-14 show a sequence for clamping an upper and lower structure,800 and 802, using the fastener system 100. In particular, FIG. 8 showsthe fastener system 100 prior to insertion through bores, 804 and 806,in the upper structure 800 and the lower structure 802, respectively,slated for clamping by the system. In one example, the upper structure800 may be a floor panel in an aircraft and the lower structure 802 maybe a floor beam. However, the fastener system 100 may be used to clampnumerous structures in other aerospace components as well as structuresin other fields such as construction, the maritime industry, theautomotive industry, etc.

In FIG. 8 the fastener system 100 is in the disengaged configuration toenable easy insertion through the bores 804 and 806. When the fastenersystem 100 is in the disengaged configuration the feet 148 are partiallymated with the openings 146. In such a configuration, the openings 146substantially inhibit movement of the collet body 106 with regard to thesleeve 104. As shown, the upper bore 804 has a greater diameter 808 thana diameter 810 of the lower bore 806. Moreover, the upper bore 804 maybe sized to mate with the facetted collar 140 in the sleeve 104. Forinstance, the upper bore and facetted collar may have a correspondingfemale and male hexagonal shape. In this way, the upper bore 804 allowsaxial movement of the sleeve through the bore and restricts (e.g.,substantially inhibits) rotation of the sleeve 104 with regard to thebore. However, in other examples, a portion of the sleeve may bepositioned external to the bore 804 and a tool may be used to restrictrotational movement of the sleeve.

FIG. 9 shows the upper structure 800 and the lower structure 802 broughtinto contact with one another and the fastener system 100 insertedthrough the bores, 804 and 806, in the upper and lower structures, 800and 802, shown in FIG. 8. FIG. 9 also shows a portion of the stud 102positioned above the upper structure 800.

FIG. 10 illustrated a side view of the fastener system 100 and the upperand lower structures, 800 and 802, shown in FIG. 9. As illustrated, aportion of the sleeve 104 including the openings 146 extends below thelower structure 802. Conversely, the head 110 of the stud 102 extendsabove the upper structure 800. FIG. 10 also shows a viewing plane 1000indicating the cross-sectional view illustrated in FIG. 11.

FIG. 11 shows the fastener system 100 in the disengaged configuration.FIG. 11 also shows the facetted collar 140 in the sleeve 104 in contactwith an upper surface 1100 of the lower structure 802. In this way, thesleeve 104 can be inhibited from sliding through the bore 806 in thelower structure 802. Additionally, in the disengaged configuration,shown in FIG. 11, the stud 102 is allowed to spin freely due to thefirst reduced diameter section 120 of the stud 102 being aligned withthe interior threaded section 144 of the sleeve 104.

FIG. 12 depicts the fastener system 100 in an engaged configurationwhere the stud 102 is advanced into the sleeve 104 via rotation of thestud 102. Advancing the stud 102 into the sleeve 104 and collet body 106pushes the feet 148 outwardly in radial directions such that theyprotrude out of the openings 146. As such, the upper surfaces 166 of thefeet 148 may act as a lower clamping surface. FIG. 12 also shows thelower surface 300 of the head 110 of the stud 102 in contact or nearcontact with an upper surface 1200 of the upper structure 800. Thus, thelower surface 300 of the head 110 may therefore act as an upper clampingsurface. Furthermore, when the fastener system 100 is in the engagedconfiguration the lower sides 152 of the openings 146 are in contact ornear contact with the lower surfaces 172 of the feet 148. When suchcontact occurs forces are transferred from the sleeve to the feet

FIG. 13 shows the fastener system 100 in the engaged configuration wherethe stud 102 is further advanced into the sleeve 104. Advancing the stud102 into the sleeve 104 further decreases the distance between the feet148 and the head 110 of the stud 102 to generate a clamping force tohold the upper structure 800 to the lower structure 802. In particular,the upper surfaces 166 of the feet 148 are in contact with the lowerstructure 802 and the lower surface 300 of the head 110 of the stud 102is in contact with the upper structure 800 to provide engagement betweenthe structures. It will be appreciated that the directions of theclamping forces may in some cases be parallel to the central axis of thefastener system. Furthermore, when fastener system is engaged (e.g.,fully engaged) the feet 148 of the cantilever legs 158 see shear stresscreated by the tension in the fastening system (i.e., upward force ofthe sleeve and the downward reaction or static reaction generated by thestructure being fastened). Specifically, the axial load in the fastenersystem is transferred from the sleeve 104 to the feet 148 of the colletbody 106 and then to the lower structure 802. To enable the forcetransfer between the feet 148 and the sleeve 104, lower surfaces 172 ofthe feet are in contact with lower sides 152 of the openings 146.Additionally, it will be appreciated that in the engaged configurationthe upper surfaces 166 of the feet 148 may be spaced away from the uppersides 150 of the openings 146. Furthermore, in the engaged configurationthe cantilever legs 158 and feet 148 of the collet body may beprohibited or blocked from moving toward the central axis 109, in oneexample, due to the position of the stud 102. In particular, in theengaged configuration the stud 102 that has opened the legs may bepositioned and contoured to prevent the cantilever legs 158 fromretracting into the openings 146. Furthermore, the lower surfaces 172 ofthe feet 148 may be correspondingly contoured with the lower sides 152of the openings 146. For instance, the lower surfaces 172 of the feet148 and the lower sides 152 of the openings 146 may be planar. In suchan example, the contact forces will hold these two flat surfacestogether (in contact) and prevent rotation towards the central axis 109.However, in other examples, the stud 102 may be configured to block thecantilever legs 158 from closing and the feet 148 may not be in directcontact with the lower surfaces 172 of the openings 146.

Additionally, outer surfaces 1300 of the cantilever legs 158 may beadjacent to (e.g., near contact or direct contact) an inner surface 201of the sleeve 104 when the fastener system 100 is in the engagedconfiguration, in one example. It will be appreciated that the outersurfaces 1300 of the cantilever legs 158 and the inner surface 201 ofthe sleeve 104 may have a small amount of clearance there between, dueto design choice and/or manufacturing tolerances.

FIG. 14 depicts the fastener system 100 with the stud 102 even furtheradvanced into the sleeve. Advancing the stud into the sleeve 104 allowsan additional clamping force to be exerted on the upper structure 800and the lower structure 802 such that the lower structure is compressed.In this way, the fastener system can be used to securely clamp twostructures to one another.

FIG. 15 shows another example of a fastener system 1500. The fastenersystem 1500, shown in FIG. 15, includes some components that are similarto those employed in the fastener system 100, shown in FIG. 1. Forexample, the fastener system 1500, shown in FIG. 15, includes a stud1502, sleeve 1504, collet body 1506, and bushing 1508. Theaforementioned components may have at least some similar contours and/orfunctions to those included in the fastener system 100, shown in FIG. 1.Therefore, redundant description is omitted. However, in the fastenersystem 1500, shown in FIG. 15, the collet body 1506 includes an interiorthreaded section 1510 that is configured to engage a threaded section1512 in the stud 1502. On the other hand, the sleeve 1504 includes anunthreaded interior section 1514.

FIG. 16 shows a side view of the fastener system 1500 shown in FIG. 15in an assembled state. Feet 1600 in the collet body are partially matedwith the openings 1602 in the sleeve 1504 such that the feet do notprotrude beyond the side of the sleeve. Viewing plane 1604 indicates thecross-sectional view shown in FIG. 17.

FIG. 17 shows a cross-sectional view of the fastener system 1500 shownin FIG. 16. The interior threaded section 1510 of the collet body 1506is not engaged with the threaded section 1512 of the stud 1502, in theconfiguration shown in FIG. 17. However, it will be appreciated the saidthreading may occur when the stud is advanced into the collet body. Itwill also be appreciated that advancing the threading between the colletbody 1506 and the stud 1502 will generate a clamping action similar tothe clamping action described above with regard to FIGS. 1-14. Thus, thefastener system 1500 may also achieve decoupling of the shear stressesfrom the collet body. However, in the fastener system 1500, shown inFIG. 15, the cantilever legs 1507 of the collet body 1506 see two stresscreating activities. The first stress being bending the legs open from aneutral position, similar to the first example of the fastener system,shown in FIG. 1. The second stress, corresponding to the addition of theinterior threaded section 1510 in the collet body 1506, being clampingforces that are carried directly through the cantilever legs 1507 thatalready see stress from being bent open. These two stress creatingactivities are additive and thus may load the collet more than otherconfigurations.

FIG. 18 shows another example fastener system 1800 (e.g., removablefastener system) that includes an auxiliary structure 1802 at leastpartially enclosing a sleeve 1804. Feet 1806 are shown partially matedwith openings 1808 in the sleeve 1804. The auxiliary structure 1802further includes a facetted collar 1810 and detent 1812 configured to begripped or held by a tool (e.g., automated tool). However, in otherexamples, the collar may not include a detent. Viewing plane 1814defines the cross-sectional view depicted in FIG. 19.

FIGS. 19 and 20 show a cross-sectional view of the fastener system 1800shown in FIG. 18 in two stages of disengagement. FIG. 19 shows a colletbody 1900 enclosed within the sleeve 1804. It will be appreciated thatthe sleeve 1804 and collet body 1900 may have similar characteristics orcombinations of characteristics to those that are described herein withregard to the other fastener system examples. Thus, the sleeve 1804 andthe collet body 1900 may interact (e.g., thread and unthread) with astud 1902 to engage and disengage the feet 1806.

The auxiliary structure 1802 includes a lower lip 1904 extendinginwardly toward a central axis 1905. The lower lip 1904 may have theshape of a lobe, hexagonal shelf, or other shape that inhibits axialmovement of the collar of the sleeve 1804 beyond the lower end of theauxiliary structure. Specifically, an upper surface 1906 of the lowerlip 1904 is shown in contact with a surface 1908 of a collar 1910 of thesleeve 1804. In this way, the fastener system 1800 may beself-contained, facilitating efficient tooling of the system. However,in other examples, the auxiliary structure 1802 may not include a lowerlip 1904.

FIG. 19 additionally depicts the stud 1902 partially enclosed by theauxiliary structure 1802. The auxiliary structure 1802 includes an upperstop 1912 and a lower stop 1914 limiting the axial movement of the stud1902. In particular, a head 1916 of the stud 1902 includes a protrusion1918 that is delimited by the upper and lower stops, 1912 and 1914. Inthis way, the head 1916 of the stud 1902 may be kept within theauxiliary structure 1802 to reduce the profile of the fastener system1800 and protect the head of the stud. It will also be appreciated thatthe interior portion 1920 in the auxiliary structure where the head 1916of the stud 1902 resides enables rotation of the head 1916. Forinstance, the interior portion 1920 may be cylindrical in shape and havea larger diameter than the head 1916.

In FIG. 19 a gap 1922 is shown between the lower stop 1914 and the head1916. The gap 1922 accommodates axial movement of the head when the stud1902 is fully disengaged from the sleeve 1804 and collet body 1900.Movement of the head upwards allows the unthreaded section 1924 of thestud 1902 to align with the interior threaded section 1926 of the sleeve1804, enabling free rotation of the stud with regard to the sleeve.

An interior portion 1928 of the auxiliary structure 1802 may beconfigured to allow axial movement the sleeve there through but limit(e.g., inhibit) rotation of the sleeve 1804. Such functionality may beachieved by contouring the interior portion such that a facetted collar1930 of the sleeve 1804 mates therein. For instance, the interiorportion and the facetted collar may have associated hexagonal shapes.

FIG. 20 shows the fastener system 1800 with the head 1916 of the stud1902 driven downward into contact with the lower stop 1914.Specifically, the protrusion 1918 in the head 1916 may be in contact ornear contact with the lower stop 1914. Driving the stud downward alsoinduces engagement between a threaded section 2000 of the stud 1902 andthe interior threaded section 1926 of the sleeve 1804. FIG. 20 alsoshows the auxiliary structure 1802 with the lower lip 1904 functioningto retain the sleeve 1804, as previously mentioned.

FIG. 21 shows the fastener system 1800, illustrated in FIGS. 18-20 priorto clamping an upper structure 2100 to a lower structure 2102. Againboth the upper and lower structures include bores 2104 and 2106,respectively. FIG. 22 depicts a lower surface 2200 of the auxiliarystructure 1802 in contact with the upper structure 2100. The lowerauxiliary structure surface 2200, therefore, acts as an upper clampingsurface. As in the case of the previous fastener examples, uppersurfaces 2202 of feet 1806 function as a lower clamping surface.

FIG. 22 also shows the stud 1902 with a lower unthreaded section 2204that may have a greater diameter than an upper threaded section 2206.However, the lower unthreaded section 2204, in other examples, may havea diameter that is smaller than or equal to the diameter of the upperthreaded section 2206. Furthermore, the lower unthreaded section 2204has a diameter 2203 that is greater than an inner diameter 2205 of athreaded section 2207 of the sleeve 1804. In this way, the fastenersystem 1800 may be locked together and act as a self-contained system.As a result, the system may be easily grasped and pulled out of a bore.The lower unthreaded section 2204 smoothly urges the cantilever legs2208 outward with reduced abrasion when the slid there through. Thelower unthreaded section 2204 is attached (e.g., press fit, braised,bonded, threaded, etc.,) to the stud 1902 as a separate component, inthe illustrated example. The lower unthreaded section 2204 thereforeacts as an elongated bushing and performs a similar function. However,in other instances, the lower unthreaded section 2204 may include of aregion without threads on the stud 1902, a bushing, an elongatedbushing, or any combination of bushings and regions without threads.Furthermore, as previously discussed, in other examples, the collet body1900 may alternatively include the threaded section that engages withthe stud.

FIG. 23 illustrates another example of a fastener system 2300. Thefastener system 2300, shown in FIG. 23, again includes a stud 2302, anauxiliary structure 2304, a sleeve 2306, and a collet body 2308. It willbe appreciated that the stud 2302, sleeve 2306, and collet body 2308 mayhave any of the features or combinations of the features of the studs,sleeves, and collet bodies in any of the fastener systems describedherein.

However, in FIG. 23 the auxiliary structure 2304 includes an upper stop2310 and a lower stop 2312 that substantially inhibit axial movement ofthe head 2314 of the stud 2302. Thus, the upper stop 2310 is nearly incontact with an upper surface 2316 of the head 2314 while the lower stop2312 is in contact with a lower surface 2318 of the head 2314. Thus, asmall gap may exist between the upper stop 2310 and the head 2314 thatmay be necessitated by manufacturing constraints, in some examples. Thistype of fastener system may be desirable in applications with packagingconstraints. For example, it may be desirable in some applications todiminish the vertical profile of the system. Furthermore, theconfiguration of the fastener system, shown in FIG. 23, does not freespin in reverse. Free spin is an optional feature of the fastener systemthat enables the stud 2302 to freely rotate with regard to the sleeve2306 and the collet body 2308 when the stud is completely unthreadedfrom the sleeve, as previously discussed. A fastener systemconfiguration that does not free spin in reverse may be desired by somerobotic manufacturers, due to the fact that some robots, in reverse,will sense the spike in torque, referred to as a hard-stop, when thefastener bottoms out (e.g., goes solid and acts as if everything isfixedly coupled together) in reverse.

It will be appreciated that in some instances the hard stop feature ofthe fastener may be included in any of the examples of the fastenersystem or combinations of the fastener systems, described herein. Thebottoming out of the fastener is shown in the detail view of the threadsengagement in FIG. 23. FIG. 23 also shows the auxiliary structure 2304including a lower lip 2320 functioning to retain the sleeve 2306, aspreviously mentioned.

FIG. 24 shows another example of a fastener system 2400 and FIG. 25shows a cross-section of the fastener system. Viewing plane 2402 denotesthe cross-sectional view shown in FIG. 25. As depicted in FIG. 25, thefastener system 2400 includes an auxiliary structure 2500 with a stop2502 preventing a head 2504 of a stud 2506 from traveling into aninterior portion 2508 of the auxiliary structure 2500. It will beappreciated that an interior surface 2510 of the stop 2502 isunthreaded, in the depicted example. Therefore, the auxiliary structuremay slide up and down freely with regard to the stud 2506 and a sleeve2512. However in other instances, the stop 2502 may have an interiorthreaded section. FIG. 25 also shows the auxiliary structure 2500including a lower lip 2532 functioning to retain the sleeve 2512, aspreviously mentioned. FIG. 25 additionally shows the fastener system2400 including a collet body 2516 that may have at least some of thefeatures, functions, etc., of the other collet bodies described herein.FIG. 25 also shows a bushing 2530. The bushing 2530 and the lower lip2532 may function similarly to the previously described bushings andlower lips. FIG. 25 shows the fastener system 2400 in a disengagedconfiguration where the stud 2506 is not threaded into the sleeve 2512.However, in the fastener system 2400 when the stud 2506 is threaded intothe sleeve, in an engaged configuration, the head 2504 of the stud 2506moves closer to (e.g., axially translate in a downward direction) thestop 2502. Specifically, in some examples, when the stud 2506 is fullythreaded into the sleeve 2512 the head 2504 of the stud may come intocontact with the stop 2502. Moreover, during the initial phase saidthreading (e.g., prior to the head 2504 contacting the stop 2502) therelative position of the auxiliary structure 2500 and the sleeve 2512may remain unchanged, in some examples. However, during a later phase insaid threading (e.g., subsequent to the head 2504 contacting the stop2502) the sleeve 2512 may axial translate upwards into the auxiliarystructure 2500. It will be appreciated that this feature may be includedin any of the examples of the fastener system or combinations of thefastener systems, described herein.

FIG. 26 shows an example of a sleeve 2600 and collet body 2602 that maybe included in any of the fastener systems described herein. As shown,the sleeve 2600 includes two openings 2604 and the collet body 2602includes two cantilever legs 2606 while the previous embodiments of thefastener system include three sleeve opening and correspondingcantilever legs. However, fasteners with a lower or greater number ofopenings and cantilever legs have been envisioned.

FIG. 27 shows another example fastener system 2700 where a stud 2702includes an upper threaded section 2704, an unthreaded section 2706, anda lower threaded section 2708. In the engaged configuration shown inFIG. 27, the lower threaded section 2708 urges cantilever legs 2710outward through openings 2712 in a sleeve 2714. Specifically in theexample illustrated in FIG. 27, the lower threaded section 2708 extendsto an end 2716 of the stud 2702. However, in other instances, the lowerthreaded section 2708 may not fully extend down the stud 2702.

FIGS. 28-33 show another embodiment of a fastener system 2800. It willbe appreciated that the fastener system 2800 may include at least aportion of the structural and/or functional features of any of thefastener systems described herein. Moreover, combining features fromthree or more fastener systems have also been envisioned.

FIG. 28 shows an exploded view of the fastener system 2800. The fastenersystem 2800 again includes a stud 2802, a collet body 2804, and a sleeve2806. The sleeve 2806 includes openings 2808 designed to mate with feet2810 of cantilever legs 2812 in the collet body 2804 when the fastenersystem 2800 is assembled and clamping upper and lower structures (e.g.,work pieces).

Additionally, the fastener system 2800 includes a locking ring 2814. Thelocking ring 2814 is designed to retain the stud 2802 and collet body2804 within the sleeve 2806. The locking ring 2814 includes a slit 2815allowing for expansion/contraction of the locking ring during fastenerassembly. In this way, fastener assembly may be simplified andefficiently carried out. In the depicted example, the locking ring 2814has an inner diameter 2816 that is greater than a diameter 2818 of areduced diameter section 2820 of the stud 2802 and less than a diameter2822 of a lower threaded section 2824 of the stud 2802. In this way, thereduced diameter section 2820 of the stud 2802 may travel axially withthe sleeve 2806 while preventing the lower threaded section 2824 of thestud 2802 as well as a head 2826 of the stud from axially egress fromthe sleeve 2806. As such, the components in the fastener system can bekept together during installation and removal of the fastener.Therefore, the likelihood misplaced components during fastenerinstallation and removal is reduced (e.g., prevented).

The lower threaded section 2824 of the stud 2802 may, in one example, bea fully formed thread that forms an angle at a crest. However, in otherexamples, the lower threaded section 2824 may be a truncated thread. Thetruncation adds strength to the crest of the threads. Such strength maybe beneficial and toughen the threads when they are pushing against thecantilever legs 2812 of the collet body 2804. Furthermore, by providinga stud with an expanded diameter section at the end of the stud 2802away from the head as opposed to a bushing, the strength of the stud maybe increased and the assembly of the fastener system may be simplified,thereby reducing manufacturing costs.

In the illustrated example, the reduced diameter section 2820 of thestud 2802 includes an unthreaded section 2828 and a threaded section2830. In the illustrated example, the diameters of the threaded section2830 and the unthreaded section 2828 of the reduced diameter section2820 of the stud 2802 are equivalent. However, in other examples, thediameter along the reduced diameter section of the stud may vary alongits length. In other examples, the reduced diameter section may not bethreaded.

In the example, shown in FIG. 28, the sleeve 2806 includes a lowerthreaded section 2832 and an upper threaded section 2833 designed tothreadingly engage with the lower threaded section 2824 of the stud2802. The lower threaded section 2832 and the upper threaded section2833 are positioned in an aperture 2834 of the sleeve 2806. Both of thethreaded sections may be designed to threadingly engage with the lowerthreaded section 2824 of the stud 2802. It will be appreciated thesleeve 2806 may include either the upper threaded section or the lowerthreaded section, in other examples. On the other hand, the collet body2804 does not include a threaded section and in contrast includes anunthreaded interior surface 2835. However, as previously discussed, insome configurations, the collet body 2804 may include a threaded sectionthreadingly engaging with the stud 2802.

The sleeve 2806 also includes a lower reduced diameter section 2836having an unthreaded outer surface 2838. The lower reduced diametersection 2836 may protect the stud 2802 during installation/removal ofthe fastener system 2800, for example.

FIG. 29 shows an assembled view of the fastener system 2800. Again, thestud 2802, collet body 2804, and sleeve 2806 are illustrated. It will beappreciated that the fastener system 2800 shown in FIG. 29 is in adisengaged configuration. A viewing plane 2900 defining thecross-sectional view shown in FIG. 30 is depicted in FIG. 29.

FIG. 30 shows a cross-sectional view of the fastener system 2800. Thestud 2802, collet body 2804, and sleeve 2806 are again shown. The sleeve2806 includes a body 3000 having the openings 2808, in the illustratedexample. The locking ring 2814 is also shown in FIG. 30. As illustrated,the locking ring 2814 is positioned in a recess 3002 of the sleeve 2806.As shown, the locking ring 2814 at least partially circumferentiallysurrounds the reduced diameter section 2820 of the stud 2802 and limitsaxial movement of the threaded section 2824 of the stud 2802 beyond thecentral aperture of the sleeve 2806.

Cantilever legs 2812 of the collet body 2804 are also shown in FIG. 30.The cantilever legs 2812 are in a neutral position in FIG. 30.Specifically, the cantilever legs 2812 extend inward in the neutralposition. As such, the cantilever legs 2812 may flex outwardly whenmated with openings 2808 in the sleeve 2806. However, other neutral legpositions have been envisioned. The enlarged area in FIG. 31 isindicated at 3004.

FIG. 31 shows an enlarged view of a portion of the fastener system 2800.The threaded section 2824 of the stud 2802 is shown in contact with thecantilever legs 2812 of the collet body 2804. Additionally, thecantilever legs 2812 are shown positioned in openings 2808 in the sleeve2806. As show, a gap 3100 exist between a portion of an outer surface3102 of the cantilever legs 2812 and an interior surface 3104 of thesleeve 2806.

The locking ring 2814 in the fastener system 2800 is also shown in FIG.31. The locking ring 2814 is shown contacting the threaded section 2824of the stud 2802. In this way, the locking ring 2814 may limit the axialmovement of the stud 2802, thereby retaining components in the system.However, it will be appreciated that the locking ring 2814 allows thereduced diameter section 2820 to axial translate with regard to thering, allowing for the intended clamping action in the system.

The threaded section 2824 of the stud 2802 is also shown contactinginterior surfaces 3106 of the cantilever legs 2812. It will beunderstood that downward movement of the threaded section 2824 of thestud 2802 further expands the cantilever legs 2812. The threads 3008 inthe threaded section 2824 may be fully formed, in one example. However,in other examples, the threads 3008 in the threaded section 2824 may betruncated.

The lower threaded section 2832 of the sleeve 2806 is also shown in FIG.31. As previously discussed, the lower threaded section 2832 of thesleeve 2806 mates with the lower threaded section 2824 of the stud 2802.

FIG. 32 shows a cross-sectional view of the fastener system 2800 in anengaged configuration where the feet 2810 of the cantilever legs 2812extend through the openings 2808 in the sleeve 2806. It will beappreciated that threading the lower threaded section 2824 of the stud2802 into the lower threaded section 2832 of the sleeve 2806 places thefastener system 2800 in the engaged configuration. The enlarged area inFIG. 33 is indicated at 3200.

FIG. 33 shows a detailed view of a portion of the fastener system 2800.As shown, a gap 3300 exist between the outer surface 3102 of thecantilever legs 2812 and the interior surface 3104 of the sleeve 2806.This clearance zone allows the cantilever legs 2812 to expand to agreater diameter when interacting with the lower threaded section 2824of the stud 2802. In this way, mechanical binding and leg deformationcaused by over-extension of the cantilever legs 2812 may be avoided.Furthermore, designing the cantilever legs 2812 in this manner allowsthe legs to be repeatedly expanded and contracted as the stud 2802 isthreaded/unthreaded into/from the sleeve 2806 without permanentdeformation.

Furthermore, the feet 2810 are in contact with the lower threadedsection 2824 (e.g., reduced diameter section) of the stud 2802, in theillustrated example. Such an arrangement may provide a desired loaddistribution in the fastener system. For instance, a large amount (e.g.,the majority) of the loads experienced by the fastener may betransferred to the sleeve, in such a configuration. As such, transfer ofthe loads to selected sections in the fastener allows the fastener to bedesigned with increased load carrying capabilities and reduces thelikelihood mechanical binding, leg degradation (e.g., permanentdeformation, failure, etc.), etc.

FIGS. 34-37 show an engagement sequence (e.g., clamping up sequence) ina fastener system 3400. FIGS. 34-37 show the fastener system 3400including the stud 3402, collet body 3404 with cantilever legs 3406having feet 3407 and a sleeve 3408 with openings 3410. Specifically,FIGS. 34-37 specifically show the fastener system 3400 in various stagesof increasing clamping engagement. It will be appreciated that threadingthe stud further into the sleeve provides increasing fastener clampingengagement.

As shown in FIG. 34, the stud 3402 begins pushing the feet 3407 of thecantilever legs 3406 through the openings 3410. As the stud 3402 isadvanced with regard to the sleeve 3408, induced via stud rotation, thecantilever legs 3406 are moved further outward to facilitate structure(e.g., work piece) clamping. Additionally, a gap 3412 exists between aninner surface 3416 of the sleeve 3408 and surfaces 3418 of thecantilever legs 3406. As the fastener system 3400 is transitioned intoan engaged configuration the size of the gap 3412 changes due to theflexion characteristics of the cantilever legs 3406.

FIG. 35 shows the feet 3407 of the cantilever legs 3406 extendingfurther through the openings 3410. An increased diameter section 3500 ofthe stud 3402 pushes the feet 3407 of the cantilever legs 3406 furtheroutward. In the configuration shown in FIG. 35 the legs areover-expanded as the legs interact with the increased diameter sectionof the stud. In other words, the legs radially expand beyond a clampingposition. FIG. 35 also depicts a smaller gap between the cantilever legs3406 and the inner surface 3416 of the sleeve 3408 when compared to theconfiguration of the fastener system in FIG. 34. It will be appreciatedthat the smaller gap is caused by increased outward flexion in thecantilever legs 3406.

The increased diameter section 3500 of the stud 3402 has a largerdiameter than a reduced diameter section 3502 of the stud 3402. In oneexample, the reduced diameter section 3502 of the stud 3402 may beunthreaded. However, in other examples, the reduced diameter section3502 of the stud 3402 may include a threaded section and an unthreadedsection, as previously discussed. Furthermore, the increased diametersection 3500 of the stud 3402 may be threaded.

FIG. 36 shows the feet 3407 of the cantilever legs 3406 extendingthrough the openings 3410 in the sleeve 3408. As such, a portion of theouter surfaces 3418 of the cantilever legs 3406 are in face sharingcontact with the inner surface 3416 of a lower structure 3600.

FIG. 37 shows the fastener system 3400 in an engaged configuration thatclamps a lower structure 3600. Specifically, an upper surface 3700 ofthe feet 3407 is in contact with an outer surface 3702 with the lowerstructure 3600. As previously, discussed the fastener system 3400 mayclamp an upper structure (not shown). In the clamping configuration ofthe fastener system 3400, shown in FIG. 37 a large amount of shearstress is transferred from the cantilever leg feet 3407 to the sleeve3408. In this way, the shear stress is essentially decoupled from thecollet body 3404. As such, a more robust fastener is provided whichefficiently transfers these stresses to selected components in thesystem designed to carry the loads. The likelihood of fastenerdegradation as well as the stresses impeding the intended operation ofthe fastener is therefore substantially reduced.

FIGS. 38-42 show another example of a fastener system 3800. The fastenersystem 3800 again includes a stud 3802, a collet body 3804, a sleeve3806, and a bushing 3808.

FIG. 38 specifically shows the stud 3802 including a threaded section3810 and a first unthreaded section 3812 (e.g., decreased diameterunthreaded section) and a second unthreaded section 3814 (e.g.,increased diameter unthreaded section). When assembled the bushing 3808may be mated with the second unthreaded section 3814 of the stud 3802.It will be appreciated that the first unthreaded section 3812 of thestud functions to allow the stud 3802 to spin freely when backed out ofa threaded section 3816 of the collet body 3804. Again, cantilever legs3818 in the collet body 3804 are shown including feet 3820. Whenassembled, the feet 3820 extend into openings 3822 in the sleeve 3806.The degree to which the fastener system 3800 is clamped up dictates thedegree to which the feet 3820 extend through the openings 3822 in thesleeve 3806, as previously discussed.

FIG. 39 shows an assembled view of the fastener system 3800, shown inFIG. 38. A viewing plane 3900 defining the cross-sectional view shown inFIGS. 40-43, is indicated in FIG. 39.

FIG. 40 shows the first unthreaded section 3812 of the stud 3802 inaxial alignment with the threaded section 3816 of the collet body 3804.As such, the stud 3802 may freely spin with regard to the collet body3804. In this way, the chance of damaging the fastener when unclampingthe fastener is reduced. For instance, when the stud 3802 is unthreadedfrom the sleeve 3806 the second unthreaded section will align with thethreaded section 3816 of the sleeve 3806. Consequently, the stud 3802will freely rotate with regard to the sleeve 3806. As a result, axialseparation between the stud 3802 and the sleeve 3806 is essentiallylimited to prevent the bushing 3808 from being damaged.

Additionally, the bushing 3808 and threaded section 3810 of the stud3802 work in conjunction with the second unthreaded section 3814 of thestud 3802 and cantilever legs 4000 to collectively trap and lock thecomponents in the fastener together.

FIG. 41 shows a detailed view of a section of the fastener system 3800shown in FIG. 40. FIG. 41 shows the diameter 4100 of the threadedsection 3810 of the stud 3802 exert an axial force on the cantileverlegs 3818 responsive to rotation of the stud via installation personneloperating a manual tool or an automated tooling apparatus.

FIG. 42 shows the fastener system 3800 with the stud 3802 furtherrotated into the sleeve 3806. Responsive to the axial translation of thestud 3802 with regard to the sleeve 3806, the threaded section 3810 ofthe stud 3802 pushes the feet 3820 of the cantilever legs 3818 throughthe openings 3822 in a body 4200 of the sleeve 3806. The enlarged areain FIG. 43 is indicated at 4202.

FIG. 43 shows a detailed view of the fastener system 3800, shown in FIG.42. As shown, the cantilever legs 3818 are nominally opened and ridingon the stud 3802. It will be appreciated that the configuration of thefastener system 3800 shown in FIG. 43 may be a desirable load-carryingconfiguration. In such a configuration the threaded section 3810 of thestud 3802 fully engages (e.g., fully engages) with the threaded section3816 of the body 4200 of the sleeve 3806.

FIGS. 44-47 show another example of a fastener system 4400. The fastenersystem 4400 again includes a stud 4402, a collet body 4404, and a sleeve4406. The stud 4402 in the system includes an upper unthreaded section4410, an upper threaded section 4408, a lower unthreaded section 4412,and a lower threaded section 4414.

FIG. 44 shows the sleeve 4406 including an upper threaded section 4416and a lower threaded section 4418. Both the threaded sections 4416 and4418 of the sleeve 4406 are included in an interior aperture of the stud4402.

The collet body 4404 includes a slit 4420. Surfaces 4422 of the colletbody 4404 define the boundary of the slit 4420. In the depicted example,the surfaces 4422 extend down sides of cantilever legs 4424 of thecollet body 4404. It will be appreciated that the slit 4420 iscircumferentially positioned between two of the cantilever legs 4424 ofthe collet body 4404, in the illustrated example. However, slit 4420 mayhave other profiles, in other examples. For instance, the slit mayextend down a leg in the collet body, splitting the leg in two. The slit4420 may accommodate radial expansion and retraction of the stud 4402during installation and removal of the fastener system 4400.Specifically, it will be appreciated that the split collet body 4404 mayhelp facilitate insertion of the collet body into the sleeve 4406. Thismay be particularly useful when the sleeve 4406 includes both an upperand lower threaded section that axially protrude into the centralaperture in the sleeve 4406. It will be appreciated that the lowerthreaded section 4414 of the stud 4402 interacts with cantilever legs4424 to radially expand the legs when the fastener is brought intoclamping engagement with work pieces.

FIG. 45 shows an assembled view of the fastener system 4400. Viewingplane 4500 defines the cross-sectional view shown in FIGS. 45-46.

FIG. 46 shows the fastener system 4400 in an engaged configuration(e.g., clamping configuration). As shown, the lower unthreaded section4412 of the stud 4402 is aligned with the upper threaded section 4416 ofthe sleeve 4406. As previously discussed, alignment between theunthreaded section 4412 of the stud 4402 and the upper threaded section4416 of the sleeve 4406 allows the stud to freely rotate with regard tothe sleeve 4406. To further engage the stud 4402 with the sleeve 4406the stud must be moved axially downward with regard to the sleeve 4406to initiate engagement between the upper threaded section 4408 of thestud 4402 and the upper threaded section 4416 of the sleeve 4406. Inthis way, the stud 4402 may be initially guided through the sleeve 4406during an initial stage of fastener clamping. Additionally, thecantilever legs 4424 are in a neutral position in the configurationshown in FIG. 45. In such a configuration, feet 4600 of the cantileverlegs 4424 only partially extend through openings 4602 in the sleeve4406.

FIG. 47 shows the fastener system 4400 in an engaged configuration. Asshown, the upper threaded section 4408 of the stud 4402 is interactingwith the cantilever legs 4424 to expand the legs such that they radiallyextend through the openings 4602 in the sleeve 4406. In the fastenerconfiguration in FIG. 47 the feet 4600 extend through the openings 4602due to the outward flexion of the cantilever legs 4424 caused by theinteraction between the upper threaded section 4408 of the stud 4402 andthe cantilever legs. FIG. 47 also shows the upper threaded section 4408of the stud 4402 in the fastener system 4400 engaging with the lowerthreaded section 4418 of the sleeve 4406.

FIGS. 1-47 show example configurations with relative positioning of thevarious components. If shown directly contacting each other, or directlycoupled, then such elements may be referred to as directly contacting ordirectly coupled, respectively, at least in one example. Similarly,elements shown contiguous or adjacent to one another may be contiguousor adjacent to each other, respectively, at least in one example. As anexample, components laying in face-sharing contact with each other maybe referred to as in face-sharing contact. As another example, elementspositioned apart from each other with only a space there-between and noother components may be referred to as such, in at least one example. Asyet another example, elements shown above/below one another, at oppositesides to one another, or to the left/right of one another may bereferred to as such, relative to one another. Further, as shown in thefigures, a topmost element or point of element may be referred to as a“top” of the component and a bottommost element or point of the elementmay be referred to as a “bottom” of the component, in at least oneexample. As used herein, top/bottom, upper/lower, above/below, may berelative to a vertical axis of the figures and used to describepositioning of elements of the figures relative to one another. As such,elements shown above other elements are positioned vertically above theother elements, in one example. As yet another example, shapes of theelements depicted within the figures may be referred to as having thoseshapes (e.g., such as being circular, straight, planar, curved, rounded,chamfered, angled, or the like). Further, elements shown intersectingone another may be referred to as intersecting elements or intersectingone another, in at least one example. Further still, an element shownwithin another element or shown outside of another element may bereferred as such, in one example.

FIG. 48 shows a method 4800 for operating a fastener system. The methodmay be implemented by any of the fastener systems and tooling apparatusor combinations of the fastener systems and tooling apparatusesdescribed above with regard to FIGS. 1-47. However, in other examples,the method may be implemented by other suitable fastener systems and/ortooling apparatuses.

Next at 4802 the method includes mating feet of a plurality ofcantilever legs in a collet body with a plurality of openings in asleeve in the fastener system. Such mating may include steps 4804 and4806. At 4804 the method includes inwardly bending the feet and at 4806the method includes axially inserting the collet body into a centralaperture in the sleeve.

At 4808 the method includes inserting the stud through the center of thesleeve and imbedded collet body. Next at 4810 the method includesattaching a bushing to an end of the stud. Attaching the bushing to thestud may include welding, press fitting, braising, adhesively bonding,combinations thereof, etc.

At 4812 the method includes inserting the fastener system through boresin an upper and lower structure. At 4814 the method includes threading athreaded section of the stud into an interior threaded section in one ofthe collet body and the sleeve. This threading may include steps4816-4822. At 4816 the method includes, rotating the stud by a firstamount so that the feet only partially extend through the plurality ofopenings. In this way, the stud may be partially threaded into thesleeve without pushing the feet out of the openings. It will beappreciated that the fastener system is in a disengaged configuration instep 4816.

At 4818 the method includes rotating the stud by a second amount toapply an outward radially force on the cantilever legs to place thefastener system in an engaged configuration where the feet extendradially outward from the openings. Thus, the feet may clamp a lowerstructure while an upper section of the system, such as the stud head orauxiliary structure, may clamp an upper structure. At 4820 the methodincludes rotating the stud by a third amount to create travel of thesleeve and the collet body. Next at 4822 the method includes rotatingthe stud by a fourth amount to induce a desired clamping force. In thisway, the fastener system may exert a targeted clamping force on thestructures. It will be appreciated that the different stages of studrotation may take place in succession (e.g., direct succession) duringfastener engagement, in some examples.

At 4824 the method includes unthreading the threaded section of the studfrom the interior threaded section. In one example, when the stud isunthreaded the stud may freely rotate within the collet body and thesleeve. The free rotation of the stud prevents damage caused byunthreading of the stud from the sleeve to a greater degree than isnecessitated. However, in other examples, the fastener system may not bedesigned to enable free spin of the stud. In such an example, the studmay be unthreaded until a spike in toque is sensed by a toolingapparatus or a person.

The technical effect of providing a fastener system with openings in asleeve and cantilever legs in a collet body having feet that mate withthe openings is the decoupling of shear stressed from the collet body toenable quick, efficient, and unencumbered clamping and unclamping of thefastener system.

The invention will further be described in the following paragraphs. Inone aspect, a fastener system is provided. The fastener system includesa sleeve including a sleeve opening, a collet body at least partiallyenclosed within the sleeve, the collet body including, a crown having acrown opening, and a first cantilever leg extending from the crown andincluding a foot configured to mate with the sleeve opening when thefastener system is in an engaged configuration, and a stud extendingthrough the crown opening and including a threaded section engaging withan interior threaded section in at least one of the collet body and thesleeve.

In another aspect, a fastener system is provided. The fastener systemincludes a sleeve including a plurality of sleeve openings, a colletbody including, a crown having a crown opening, and a plurality ofcantilever legs extending from the crown, each of the plurality ofcantilever legs including a foot configured to mate with one of theplurality of sleeve openings when the fastener system is in an engagedconfiguration, and a stud extending through the crown opening andincluding a threaded section engaging with an interior threaded sectionin the sleeve, where, in the engaged configuration, the stud exerts anoutward force on the plurality of cantilever legs to push a portion ofeach of the feet outside of the corresponding sleeve opening.

In another aspect, a method for a fastener system is provided. Themethod includes mating feet of a plurality of cantilever legs in acollet body with a plurality of openings in a sleeve, and threading athreaded section of a stud into an interior threaded section in one ofthe collet body and the sleeve.

In another aspect, a fastener system is provided. The fastener systemincludes a sleeve including a sleeve opening, a collet body at leastpartially enclosed within the sleeve, the collet body including, a crownhaving a crown opening, and a cantilever leg extending from the crownand including a foot configured to mate with the sleeve opening when thefastener system is in an engaged configuration, and an auxiliarystructure at least partially extending around the sleeve having an innerdiameter that is greater than an outer diameter of the sleeve.

In another aspect, a fastener system is provided. The fastener systemincludes a sleeve including a sleeve opening, a collet body at leastpartially enclosed within the sleeve, the collet body including a crownhaving a crown opening, and a cantilever leg extending from the crownand including a foot configured to mate with the sleeve opening when thefastener system is in an engaged configuration, and a stud extendingthrough the crown opening and including a threaded section engaging withan interior threaded section in the sleeve and an unthreaded sectionpositioned below the threaded section, the unthreaded section allowingthe stud to spin freely when the threaded section of the stud isunthreaded from the interior threaded section of the sleeve.

In another aspect, a fastener system is provided. The fastener systemincludes a sleeve including a plurality of sleeve openings; a colletbody including a crown having a crown opening, and a plurality ofcantilever legs extending from the crown, each of the plurality ofcantilever legs including a foot configured to mate with one of theplurality of sleeve openings when the fastener system is in an engagedconfiguration, and a stud extending through the crown opening andincluding, a threaded section engaging with an interior threaded sectionin the sleeve, and a head positioned external to a central aperture inthe sleeve when the fastener system is in the engaged configuration, anda bushing coupled to an end of the stud.

In another aspect, a fastener system is provided. The fastener systemincludes a sleeve including a sleeve opening, a collet body at leastpartially enclosed within the sleeve, the collet body including, a crownhaving a crown opening, and a cantilever leg extending from the crownand including a foot configured to mate with the sleeve opening when thefastener system is in an engaged configuration, an auxiliary structureat least partially extending around the sleeve and including an upperstop and a lower stop limiting axial movement of a head of a studpositioned at least partially the auxiliary structure.

In another aspect, a fastener system is provided. The fastener systemincludes a sleeve including a sleeve opening, a collet body at leastpartially enclosed within the sleeve, the collet body including a crownhaving a crown opening, and a cantilever leg extending from the crownand including a foot configured to mate with the sleeve opening when thefastener system is in an engaged configuration, and an auxiliarystructure at least partially extending around the sleeve and including alower lip extending radially inward to retain a collar of the sleeve inan interior portion of the auxiliary structure.

In another aspect, a fastener system is provided. The fastener systemincludes a sleeve including a sleeve opening, a collet body at leastpartially enclosed within the sleeve, the collet body including, a crownhaving a crown opening, and a cantilever leg extending from the crownand including a foot configured to mate with the sleeve opening when thefastener system is in an engaged configuration, and an auxiliarystructure at least partially extending around the sleeve and including alower lip extending radially inward to retain a collar of the sleeve inan interior portion of the auxiliary structure, and a stud extendingthrough the crown opening and including, a threaded section engagingwith an interior threaded section in at least one of the collet body andthe sleeve, and a head extending above the auxiliary structure.

In yet another aspect, a fastener system is provided. The fastenersystem includes a sleeve including a sleeve opening, a collet body atleast partially enclosed within the sleeve, the collet body including, acrown having a crown opening, and a cantilever leg extending from thecrown and including a foot configured to mate with the sleeve openingwhen the fastener system is in an engaged configuration, an auxiliarystructure at least partially extending around the sleeve and including alower lip extending radially inward to retain a collar of the sleeve inan interior portion of the auxiliary structure, and a stud extendingthrough the crown opening and including, a threaded section engagingwith an interior threaded section in at least one of the collet body andthe sleeve, and a head that does not extend above the auxiliarystructure.

In yet another aspect, a fastener system is provided. The fastenersystem includes a sleeve including a sleeve opening, a collet body atleast partially enclosed within the sleeve, the collet body including, acrown having a crown opening, and a cantilever leg extending from thecrown and including a foot configured to mate with the sleeve openingwhen the fastener system is in an engaged configuration, an auxiliarystructure at least partially extending around the sleeve and including alower lip extending radially inward to retain a collar of the sleeve inan interior portion of the auxiliary structure, and a stud extendingthrough the crown opening and including, a threaded section engagingwith an interior threaded section in at least one of the collet body andthe sleeve, and an unthreaded section positioned below the threadedsection and configured to allow the stud to spin freely when in adisengaged configuration.

In another aspect a fastener system is provided. The fastener systemincludes a sleeve including a sleeve opening, a collet body at leastpartially enclosed within the sleeve, the collet body including, a crownhaving a crown opening, and a cantilever leg extending from the crownand including a foot configured to mate with the sleeve opening when thefastener system is in an engaged configuration, an auxiliary structureat least partially extending around the sleeve and including, a lowerlip extending radially inward to retain a collar of the sleeve in aninterior portion of the auxiliary structure, an upper stop, and a lowerstop limiting axial movement of a head of the stud positioned in aninterior portion of the auxiliary structure, and a stud extendingthrough the crown opening and including a threaded section engaging withan interior threaded section in at least one of the collet body and thesleeve.

In another aspect, a fastener system is provided that includes a sleeveincluding a sleeve opening, a collet body at least partially enclosedwithin the sleeve, the collet body including, a crown having a crownopening, and a cantilever leg extending from the crown and including afoot configured to mate with the sleeve opening when the fastener systemis in an engaged configuration, and a stud extending through the crownopening and including a threaded section engaging with an interiorthreaded section in at least one of the collet body and the sleeve,where a bushing is coupled to a distal end of the stud or the studincludes an expanded diameter section at the distal end of the stud, andwhere the bushing or the expanded diameter section of the stud radiallyexpand the cantilever leg when the stud is threaded into the interiorthreaded section in at least one of the collet body and the sleeve.

In any of the aspects or combinations of the aspects, the sleeve mayinclude the interior threaded section.

In any of the aspects or combinations of the aspects, the stud mayinclude a reduced diameter section positioned below the threadedsection.

In any of the aspects or combinations of the aspects, an axial length ofthe reduced diameter section on the stud may be equal to or greater thanan axial length of the interior threaded section of the sleeve.

In any of the aspects or combinations of the aspects, the collet bodymay include the interior threaded section.

In any of the aspects or combinations of the aspects, the firstcantilever leg may include an outer surface in contact with an innersurface of the sleeve when the fastener system is in the engagedconfiguration.

In any of the aspects or combinations of the aspects, the fastenersystem may further include a bushing coupled to an end of the stud.

In any of the aspects or combinations of the aspects, a head of the studmay be positioned external to a central aperture in the sleeve when thefastener system is in the engaged configuration.

In any of the aspects or combinations of the aspects, when the fastenersystem is in the engaged configuration, a lower surface of a head of thestud may be in contact with an upper structure.

In any of the aspects or combinations of the aspects, when the fastenersystem in the engaged configuration, an upper surface of the foot may bein contact with a lower structure.

In any of the aspects or combinations of the aspects, the firstcantilever leg may bend radially inward in a neutral position.

In any of the aspects or combinations of the aspects, the sleeve mayinclude a facetted collar spaced away from the sleeve opening.

In any of the aspects or combinations of the aspects, in a disengagedconfiguration the plurality of cantilever legs may be in neutralpositions and in the engaged configuration the plurality of cantileverlegs are in tensioned positions.

In any of the aspects or combinations of the aspects, advancingengagement between the threaded section of the stud and the interiorthreaded section may decrease a distance between an upper clampingsurface and a lower clamping surface and where the lower clampingsurface may be included in the feet and the upper clamping surface isincluded in the stud.

In any of the aspects or combinations of the aspects, the fastenersystem may further include an auxiliary structure at least partiallyextending around the sleeve.

In any of the aspects or combinations of the aspects, advancingengagement between the threaded section of the stud and the interiorthreaded section may decrease a distance between an upper clampingsurface and a lower clamping surface and where the lower clampingsurface may be include the feet and the upper clamping surface isincluded in the auxiliary structure.

In any of the aspects or combinations of the aspects, the auxiliarystructure may include an upper stop and a lower stop limiting axialmovement of a head of the stud positioned in an opening of the auxiliarystructure.

In any of the aspects or combinations of the aspects, the auxiliarystructure may include a stop having an inner diameter that is greaterthan an outer diameter of the threaded section of the stud and less thana diameter of a head of the stud.

In any of the aspects or combinations of the aspects, the auxiliarystructure may include a lower lip extending radially inward to retain acollar of the sleeve in an interior portion of the auxiliary structure.

In any of the aspects or combinations of the aspects, where threadingthe threaded section of the stud into the interior threaded may includerotating the stud to apply an outward radially force on the cantileverlegs and place the fastener system in an engaged configuration where thefeet extend radially outward from the plurality of openings.

In any of the aspects or combinations of the aspects, mating the feet ofthe plurality of cantilever legs in the collet body with the pluralityof openings in the sleeve may include inwardly bending the feet of theplurality of cantilever legs, and axially inserting the collet body intoa central aperture in the sleeve.

In any of the aspects or combinations of the aspects, the method mayfurther include unthreading the threaded section of the stud from theinterior threaded section and freely rotating the stud within the colletbody and the sleeve.

In any of the aspects or combinations of the aspects, the method mayfurther include, prior to threading the threaded section into theinterior threaded section and subsequent to mating the feet with theplurality of openings, attaching a bushing to an end of the stud.

In any of the aspects or combinations of the aspects, the stud mayinclude a reduced diameter section positioned above the threaded sectionof the stud and where the threaded section has a larger diameter thanthe reduced diameter section is and is positioned closer to an end ofthe stud spaced away from a head of the stud.

In any of the aspects or combinations of the aspects, the fastenersystem may further include a locking ring positioned in a centralaperture of the sleeve and at least partially circumferentiallysurrounding the stud and where the locking ring limits axial movement ofthe stud.

In any of the aspects or combinations of the aspects, the collet bodymay include a slit circumferentially positioned between two of theplurality of cantilever legs.

In any of the aspects or combinations of the aspects, the collet bodymay include a slit circumferentially positioned between the firstcantilever leg and a second cantilever leg included in the collet body

In any of the aspects or combinations of the aspects, the stud mayinclude a reduced diameter section positioned above the threaded sectionof the stud and where the threaded section has a larger diameter thanthe reduced diameter section is and is positioned closer to an end ofthe stud spaced away from a head of the stud and where the reduceddiameter section threadingly engages with the interior threaded sectionin the sleeve.

In any of the aspects or combinations of the aspects, the collet bodymay include a slit circumferentially positioned between two of theplurality of cantilever legs.

In any of the aspects or combinations of the aspects, the stud mayinclude a reduced diameter section adjacent to the threaded section ofthe stud and where the stud freely rotates when the reduced diametersection is aligned with the interior threaded section in at least one ofthe collet body and the sleeve.

Note that the example control and estimation routines included hereincan be used with various fastener system configurations. The controlmethods and routines disclosed herein may be stored as executableinstructions in non-transitory memory and may be carried out by atooling apparatus.

The specific routines described herein may represent one or more of anynumber of processing strategies such as event-driven, interrupt-driven,multi-tasking, multi-threading, and the like. As such, various actions,operations, and/or functions illustrated may be performed in thesequence illustrated, in parallel, or in some cases omitted. Likewise,the order of processing is not necessarily required to achieve thefeatures and advantages of the example embodiments described herein, butis provided for ease of illustration and description. One or more of theillustrated actions, operations and/or functions may be repeatedlyperformed depending on the particular strategy being used. Further, thedescribed actions, operations and/or functions may graphically representcode to be programmed into non-transitory memory of the computerreadable storage medium in the fastener system and/or tooling apparatus,where the described actions are carried out by executing theinstructions in a tooling apparatus and fastener system including thevarious components.

It will be appreciated that the configurations and routines disclosedherein are exemplary in nature, and that these specific embodiments arenot to be considered in a limiting sense, because numerous variationsare possible. For example, the above technology can be applied to abroad range of manufacturing fields such as the aerospace industry, theconstruction industry, the maritime industry, etc. The subject matter ofthe present disclosure includes all novel and non-obvious combinationsand sub-combinations of the various systems and configurations, andother features, functions, and/or properties disclosed herein.

The following claims particularly point out certain combinations andsub-combinations regarded as novel and non-obvious. These claims mayrefer to “an” element or “a first” element or the equivalent thereof.Such claims should be understood to include incorporation of one or moresuch elements, neither requiring nor excluding two or more suchelements. Other combinations and sub-combinations of the disclosedfeatures, functions, elements, and/or properties may be claimed throughamendment of the present claims or through presentation of new claims inthis or a related application. Such claims, whether broader, narrower,equal, or different in scope to the original claims, also are regardedas included within the subject matter of the present disclosure.

The invention claimed is:
 1. A fastener system comprising: a sleeveincluding a sleeve opening; a collet body at least partially enclosedwithin the sleeve, the collet body including: a crown having a crownopening; and a first cantilever leg extending from the crown andincluding a foot configured to mate with the sleeve opening when thefastener system is in an engaged configuration; and a stud extendingthrough the crown opening and including a threaded section engaging withan interior threaded section in at least one of the collet body and thesleeve; where the sleeve opening includes a lower side that ispositioned below a lower surface of the foot; where the sleeve includesthe interior threaded section; where the stud includes a reduceddiameter section positioned below the threaded section; and where anaxial length of the reduced diameter section of the stud is equal to orgreater than an axial length of the interior threaded section of thesleeve.
 2. The fastener system of claim 1, where the first cantileverleg includes an outer surface in contact with an inner surface of thesleeve when the fastener system is in the engaged configuration.
 3. Thefastener system of claim 1, further comprising a bushing coupled to anend of the stud.
 4. The fastener system of claim 1, where a head of thestud is positioned external to a central aperture in the sleeve when thefastener system is in the engaged configuration and when the fastenersystem is in the engaged configuration, a lower surface of the head ofthe stud is in contact with an upper structure.
 5. The fastener systemof claim 4, where, when the fastener system is in the engagedconfiguration, an upper surface of the foot is in contact with a lowerstructure.
 6. The fastener system of claim 1, where the first cantileverleg extends radially inward in a neutral position.
 7. A fastener systemcomprising: a sleeve including a plurality of sleeve openings; a colletbody including: a crown having a crown opening; and a plurality ofcantilever legs extending from the crown, each of the plurality ofcantilever legs including a foot configured to mate with one of theplurality of sleeve openings when the fastener system is in an engagedconfiguration; and a stud extending through the crown opening andincluding a threaded section engaging with an interior threaded sectionin the sleeve; where, in the engaged configuration, the stud exerts anoutward force on the plurality of cantilever legs to push a portion ofeach of the feet outside of the corresponding sleeve opening; where eachof the plurality of sleeve openings include an upper side, a lower side,and opposing lateral sides that extend around an upper surface, a lowersurface, and opposing side surfaces of the corresponding foot; and wherethe collet body includes a crown sized to mate with a central aperturein the sleeve that extends to a distal end of the sleeve.
 8. Thefastener system of claim 7, where, in a disengaged configuration, theplurality of cantilever legs are in neutral positions and, in theengaged configuration, the plurality of cantilever legs are in tensionedpositions.
 9. A fastener system comprising: a sleeve including a sleeveopening; a collet body at least partially enclosed within the sleeve,the collet body including: a crown having a crown opening; and acantilever leg extending from the crown and including a foot configuredto mate with the sleeve opening when the fastener system is in anengaged configuration; and a stud extending through the crown openingand including a threaded section engaging with an interior threadedsection in at least one of the collet body and the sleeve; where abushing is coupled to a distal end of the stud or the stud includes anexpanded diameter section at the distal end of the stud; where thebushing or the expanded diameter section of the stud radially expand thecantilever leg when the stud is threaded into the interior threadedsection in at least one of the collet body and the sleeve; where each ofthe plurality of sleeve openings include an upper side, a lower side,and opposing lateral sides that extend around an upper surface, a lowersurface, and opposing side surfaces of the corresponding foot; where thecollet body includes a crown with an outer diameter that is smaller thana diameter of an inner surface of the sleeve; and where the crown of thecollet body is spaced away from a head of the stud when the fastenersystem is in the engaged configuration.
 10. The fastener system of claim9, where the stud includes a reduced diameter section adjacent to thethreaded section of the stud and where the stud freely rotates when thereduced diameter section is aligned with the interior threaded sectionin at least one of the collet body and the sleeve.